Automatic decelerating air-brake equipment.



G. MACLOSKIE.

AUTOMATIC DECELERATING AIR BRAKE EQUIPMENT.

APPLICATION FILED NOV. 9.1918.

Patented Apr. 22,1919.

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rmrren srAENr oration GEORGE MACLOSKIE, or ERIE, PENNSYLVANIA, ASSIGNOR To GENERAL LEcrErc coNPANY, a coEroEA'rIoN or NEw "roan.

AUTOMATIC. DECELERATING AIR-BRAKE E il'U'IPllllElELlEPIlJ.

To all whom/it may concern: a I

Be it known that I, GEORGE MACLOSKIE, a citizen of the United States, residing at Erie, in the county of Erie, State of Pennsylvania, have invented certain new and useful Improvements in Automatic Decelerating Air-Brake Equipments, of which the following is a specification.

My invention relates to fluid pressure from the brake cylinder is automatically regulated by the speed of the train and by the amount of pressure supplied to thecyliner. r

It is a well established factthat the 00- Specification of Letters Patent.

brake systems and its object is to provide improved means whereby the fluid exhausted efficient of friction is a function of the speedy .1 low speed. Therefore, it is very desirable to apply a higher pressure when the train is' traveling at a high rate of speed than when it is traveling at a low rate of speed. In order *to prevent, however, the h-igherpressure from causing the wheels to slide when the speed has been reduced, it is necessary to provide means for gradually decreasingthe pressure in the brake cylinder as the speed decreased.

The initial pressure applied to the brakes is made proportional to the speed of the train as by moving the motormans valve to different positions and, in accordance with. my invention, when the pressure in the brake cylinder reaches a value predetermined by the position to which the motormans valve is moved, a pressure operated switch causes the operation of a magnet valve to shut ofi the supply of air to the brake cylinder. \Vhen the speed of the train has decreased to a predetermine'd speed, a magnet release.

valve is operated to gradually 'reduce the pressure in the brake cylinder to a-value which will just stop the train. p

It will be observed that if the magnet re lease valve'is operated at the same speed in all cases to exhaust the'air, the rate of retardation from this predetermined point will vary with the pressure in the brake cylinder, as it will take longer for the air at a high pressure-to exhaust than air at a lower pressure. Another feature of this invention is the provision of means whereby the magnet release valve will be operated at differconnections as follows: Pipe 2, which is con nected to a main reservoir 3, which in turn is connected to an alrcompressor 4c; tram Patented Apr. 32, 1919., Application filed November e, 1918. Serial o; eer'ze.

pipe 5, which is connected to a brake cylinder pipe v6 through a magnet valve 7 which is closed when the coil 47 thereof is energized; train pipe 8, which is directly connected to the brake cylinder 'pipe 6, and pipe 9, which is connected to exhaust. v

The m'otormans valve also has attached thereto a drum which is provided with three segments 10, 11- and 12. Three contact fingers 13, 14 and 15 are connected to the handle of the motormans valve and are arranged to make contact with the segments of the drum. The contact finger 13 is connected to the trolley 16, the contact finger 14 is connected to a conductor 17 whlch s energized when the motormans valve 1s moved to thefirst application position, andthe contact finger 15 isconnected'to a conductor 18 which is energized when the motormans valve is moved to the second appli cation position. i

The positions of the motormans valve are as follows, beginning at the extreme left;-

Emergency position in which both of the I train pipes 5 and 8 are connected to the main reservoir 3; second application position in ;which conductor 18 is connected to the trol trolley 16 and the train limb is connected to the main reservoir 3; lap position in' switch A. operates when the pressure in the brake cylinder reaches a predetermined value, 30 lbs. for example, and connects the three contacts 22, 23 and 24 together. The pressure operated switch B operates when the pressure in the brake cylinder reaches a higher value than that which operates the switch B, 50 lbs. for example, and connects the three contacts 25, 26 and 27 together.

I The. operation of these pressure operated switches is as follows:

As the pressure in the brake cylinder 19 rises, the pressure in the chamber below the pistons 28 and 28 in the switches A. and B, respectively, also rises and forces the pistons upward against the action of the compression springs 30 and 30", thereby turning the levers 32 and 32 around their respective I fulcrums 34 and 34 of the tension springs 36 and 36*, which respectively connect the lever 32 to the contact closing lever 38 and the lever 32 to the l contact lever 38*, are brought above the fulcrums 34 and 34". The action of the springs then pulls the contact levers 38 and 38 upward. By using compression springs of the proper strength in these switches, it is obvious that each switch can be madeto connect its contacts together whenthe pressure in the brake cylinder pipe reaches any de sired value. As above mentioned, the switch A operates at a lower pressure than the switch B. When the pressure in the brake pipe is reduced, the pistons 28 and 28 are moved downward thereby moving the left handends of the tension springs 36 and 36 belowthe fulcrum 34 and 34, respectively, at which time the levers 36 and 36 are returned to their normal positions by the springs 36 and 36*. This action of 'the switches does not take place until the pistons have nearly. reached their normal position, at which time most of the air is out of the brake cylinder.

41 represents the armature of one of the car motors and the relays 42 and 43 are adapted to be connected across the armature when the relay 44 is Xenergized; Normally the relays 42 and 43 are held energized by being connected to the trolley 16 by the conductor 45 and thereby maintain the circuit of the coil 46 of release magnet valve 40 open. The relays 42 and 43 are wound so that a larger currentis required to keep the armature of relay 42 attracted than is required to keep the armature of relay 43 at.- tracted. Relay 44 and coil 47 of magnet valve 7 are connected to contacts 23 and 26 by conductor 48.

The operation of the particular arrangement shown is as follows:

It will be assumed for the purpose of illustration, that when the car is operating at a speed up to 20 miles per hour, the proper rate of retardation may be obtained by mov- The left hand ends ing the motormans valve handle to the first service position and leaving it there until the car stops; that when the car is operating at a speed between 20 and 30 miles per hour, the proper rate may be obtained by moving the motormans valve handle to the second application position and leaving it there until the car stops, and that when a quick or emergency stop is desired, this may be obtained by moving the brake handle to the emergency position and leaving it there until the car stops.

If the car is operating at a speed between 20 and 30 miles per hour, and the motormans valve is moved to the second application position, air is admitted from the main reservoir 3 to the brake cylinder 19 through the train pipe 5, magnet valve 7 and brake cylinder pipe 6. Air continues to flow to the brake cylinder 19 until the pressure therein is suflicient to operate the switch B to connect the contacts 25, 26 and 27 together. Switch A will have operated at a lower pressure but the operation thereof has no effect at this time. A circuit is then completed from the trolley 16, through contact finger 13, segments 10 and 12, contact finger 15, conductor 18, contacts 27 and 26, conductor 48, to ground through the winding of relay 44 and the coil 47 of magnet valve 7 in parallel. Magnet valve 7 is thereby moved to its closed position and shuts ofi' the How of air from the train line 5 to the brake cylinder 19.

The energization of relay 44, disconnects the relays 42 and 43 from the trolley 16 and connects them across the armature of motor 41. The relay 44 lifts its armature so rapidly that the armatures of the relays 42 and 43 do not have time to drop to their lower positions before the circuit through the armature of motor 41 is closed.

It is assumed in this description that the power is disconnected from the motors of the car before the brakes are applied, but obviously means may be provided so that the above mentioned circuit for relay 44 can only be completed when the motormans controller is in the off position. Therefore, with -the power shut ofl and relay 44 energized, the armature of motor 41, by revolving in the residual field of the motor, acts as a generator and generates an electromotive force which varies with the speed of the car. Obviously a number of other. devices, such as a small motor geared to the axle of the car may be used to produce an electromotive force which is proportional to'the speed of the car. The electromotive force produced when the car is operating above a certain speed, for example, 20 miles per hour, causes sufiicient current to hold the-armatures of relays 42 and 43 in their upper position. When, however, the speed of the car has been reduced to approximately 20 miles per mamas hour, the relay 42 is so constructed that the current. flowing therethrough is insuficient to hold up its armature. The dropping of this armature closes a circuit for the release magnet valve 40 which may be traced from the trolley 16- to the contact 27 through the circuit previously described and then through contact 25, conductor 49, contacts and armature of relay 42, coil 46 of release magnet valve 40 to ground. The energization of coil 46 moves the release magnet ..valve 40 to its open position, and airfiows from the brake cylinder to atmosphere through a restricted passage 50 and a Weighted valve 60. The size of this restricted passage 50 is such as will produce a gradual decrease in the brake cylinder pressure Which is proportional to the decreasing speed of the car.

The weight of the valve 60 is such that normally the valve is maintained in its hotosition. When, however, the pressure below the valveisabove a certain amount the valve is moved upward to its open position and the "restricted passage 50 is connected to atmosphere through the ex haust ports of the valve 60. In the apparatus shown, the weightof the valve 60 is adjusted so that when the pressure in the brake ylinder 19 is reduced to a point which will just keep the brake shoes in engagement with wheels, the valve 60 moves to its closed position and shuts d the flow of air from the brake cylinder to the atmosphere.

Tnorder to completely release the brakes after this application of the brakes, the handle of the motormans valve 1 is moved to release position. and the air remaining in the brake cylinder 19 is exhausted through pipes 8 and 9. As soon as the pressure in the brake cylinder reaches a predetermined point below that point at which the valve 60 closes, the switches A and B are restored to their normalposition. Contacts 25, 26 and 27 are thereby disconnected from each other, whereupon the relay 44 and coils 46 Q and 47 are deenergized and relays 42 and 43 are energized. I

' It will now be assumed-that the car is moving at a speed less than 20 miles per hour and that the handle of the motormans valve is moved to the first application posil[n the same manner as above described, air is supplied to the brake cylinder 19 until the air therein reaches the pressure which operates the switch A t connect the'contacts 22, 23 and 24 together. It was assumed that this switch operated at a lower pressure than switch B and. therefore, the contacts 25, 26 and 27 are still disconnected from each other.

The connecting of contacts 23 and 24, closes a circuit from the trolley 16'through contact finger 13, segments 10 and 11, contact finger 14, conductor 17, contacts 24 and 23, conductor 48 to ground through the winding of relay 44 and the coil 47 of magnet valve 7 in multiple. The supply of air is thereby cut ofl from the brake cylinder 19, and the circuit of relays 42 and 43 disconnected from the trolley and connected to the armature 41 in the same manner as above described.

Since the car is traveling at a speed less than 20 miles an hour, the armature of motor 41 is not generating enough electromotive force to cause sufiicient current to flow to keep the armature of relay 42 in its upper position. The latter armature, therefore, drops down, but the circuit for the magnet valve 46 is not completed through wire 49 because the pressure in the brake flow to hold the armature of relay 43 in its upper position. We will assume that this takes place when the speed of the car is reduced to 10 miles per hour. When the armature of relay 43 moves to its bottom position, a circuit is closed from the trolley 16- through the circuit previously described to contact 24, then through contact 22, conductor 51, contacts and armature of relay 43, coil 46 of release magnet valve 40 to ground. Air then flows from the brake cylinder 19 to atmosphere until the pressure of the cylinder is reduced to the point where the valve 60 closes.

The brakes are completely released after this application by moving the handle of the motormans valve to release position.

In case an emergency application of the brakes is desired, the handle of the motormans valve is moved to the emergency position and the reservoir 3 isconnected directly to the brake cylinder 19 through pipe 8. Since the magnet valve 7 is by-passed, the pressure in the brake cylinder is raised to the main reservoir pressureirrespective to atmosphere through the exhaust pipe 9.

It is, of course, apparent that other means,

cylinder for operating said release valve at to the speed of the train, and also other means may be used for varying the pressure applied to the brake cylinder in pro-. portion to the speed at which the train is,

going when the pressure is applied and that such alterations and modifications may bemade in the apparatus herein disclosed with out departing from the spirit and scope of my invention, and, therefore, I do not wish to be limited to the specific apparatus shown but aim to cover by the terms of t e appended claims all such nlterations and modifications.

What I claim as new and desire to secure by \I1etters Patent of the United States, is: 1. In a fluid pressure ldrake system, a brake cylinder, a magnet release valve, means automatically operated at one speed of the train for completing a circuit for said valve when the fluid plessure' in the cylinder is above a predetermined value, and means automatically operated at a different speed forcompleting another circuit for said valve when the fluid pressure is below the predetermined value. 7

2. In combination with a vehicle, a fluid pressure brake system comprising a brake cylinder, means for applying different amounts of fluid pressure to said brake cylinder in proportion to the speed of the vehicle at the time the fluid pressure is applied, a release valve, and means controlled by the amount of pressure applied 'to said brake giftierent predetermined speeds of the ve- 3. In combination with a vehicle, a fluid pressure brake system comprising a brake cylinder, means for applying different amounts of fluid pressure to said brake cylinder in proportion to the speed of the vehicle at the time the fluid pressure is applied, a release valve, a plurality of pressure operated switches, each being arranged to be operated by a different amount of fluid pressure in said brake, and means controlled by said switches for operating said release valve at different predetermined speeds of i I the vehicle.

4. In combination with a vehicle, a fluid pressure brake system having a magnet release valve, means for producing an electromotive force proportional to the speed of the vehicle, a plurality of relays connected to said means, each of said relays being arranged to operate at a difl'erent speed of the vehicle, and a circuit for said release valve controlled by said relays.

5. In combination with a vehicle, a fluid pressure brake system having a magnet re-. lease valve, means for producing an electromotive force proportional to the speed of the vehicle, a plurality. of relays connected to said means, each of said relays being arranged to be operated at a diflerent speed of the vehicle, a plurality-of pressure operated switches, and a circuit for said release valve controlled b said relays and said switches. 6. In com ination with a vehicle, a fluid pressure brake system having a magnet release valve, means for producing an electromotive force proportional to the speed of the vehicle, a plurality of relays connected to said means, each of said ,relaystgoeing arranged to be operated at a difi'ere t speed of the vehicle, a plurality of pressure operated switches, each being arranged to be operated by a diflerent pressure, a circuit for said re lease valve jointly controlled by one of said relays and one of-saidswitches, and another circuit for said release valve jointly controlled by another of said relays and another of said switches.

7. In combination with a vehicle, a fluid pressure brake system having a magnet re lease valve, a ropelling motor for said ve-. hicle,.a plurality of relays, each being arranged to be operated by a difl'erent amount of current, means for connecting said; relays to the armature of said motor, and a circuit 1for said release valve controlled by said reays. 8. In combination with a vehicle, a fluid pressure brake system having a magnet release valve, a propelling motor for said vehicle, a plurality of relays, each of said relays being arranged to be operated by a dir ferent amount of current, means for connecting said relays to the armature of said motor when the same is revolving in the residual field of the motor, and a circuit for said release valve controlled by said relays. 9. In combination with avehicle, a fluid pressure brake system having a brake cylinder and a magnet release valve, means for producing an electromagnetic force proportional to the speed of the vehicle, two relays, each being arranged to be operated by a different amount of current to control said release valve, and means controlled by the pres sure in the brake cylinder for connecting said relays to said first mentioned means.

10. In a'fluid pressure brake system, a brake cylinder, a source of fluid pressure, a motormans valve having a plurality of positions for connecting said source to said cylinder, a magnet valve for controlling the connection between said motormans valve and said cylinder, and a circuit for said magnet valve controlled by the position of the motormans valve and the pressure in said cylinder.

11. In a fluid pressure brake system, a brake cylinder, a source of fluid pressure, a motormans valve having a plurality of positions for connecting said source to said cylinder, a magnet valve for controlling said connection, a plurality of pressure operated switches, each switch being operated by a difierent predetermined pressure in said cylinder and a circuit for said magnet valve controlled jointly by the position of the motormans valve and said pressure operated switches. 7

12. In a fluid pressure brake system, a brake cylinder, a source of fluid pressure, a motormans valve having a plurality of positions for connecting said source to said cylinder, a magnet valve for controlling the connection between said motormans valve and said cylinder, means responsive to one pressure in said cylinder for operating said magnet valve when the motormans valve is in one of said positions, and means responsive to another pressure in said cylinder for operating said magnet valve when the mo tormans valve is in another one of said positions.

inder, a magnet valve for controlling the connection between said motormans valve and said brake cylinder, a magnet release valve, and circuits for said magnet valves controlled jointly by the position of the motormans valve and the pressure in said cylinder.

14. In combination with a vehicle, a fluid pressure brake system comprising a brake cylinder, a source of fluid pressure, a motormans valve having a plurality of positions for connecting said source to said cylinder, a magnet valve for controlling the connection between said motormans valve and said brake cylinder, a magnet release valve, a circuit for said first mentioned magnet valve controlled jointly by the position of the motormans valve and the pressure in said cylinder, and a circuit for said magnet release valve controlled jointly by the speed of the vehicle, the pressure in said cylinder and the position of the motormans valve.

In witness whereof, I have hereunto set my hand this 5th day of Nov, 1918.

GEORGE MACLOSKIE. 

